Overhaul VirtFusion provider: 20 resources, 30 data sources, multipage pagination

Complete rewrite of the VirtFusion Terraform provider with full API coverage:

- 20 managed resources (server, build, SSH key, user, firewall, IP blocks, etc.)
- 30 data sources (hypervisors, packages, servers, IP blocks, self-service, etc.)
- New HTTP client with proper error handling, query parameter support, and
  automatic multipage pagination via GetAllPages (fetches all pages from
  Laravel-style paginated endpoints and merges into a single response)
- Fixed type mismatches against live API: ServerData.Suspended (int→bool),
  IPBlockData.Type (string→int), PackageData json tags (primaryStorage, etc.),
  ServerData nested CPU/Settings/Resources structure, HypervisorGroupResources
  array response
- Configurable results-per-page (default 300) on all list data sources
- Migrated CI from GitHub Actions to Gitea Actions
- Updated goreleaser config, go.mod dependencies, and examples

Verified against live VirtFusion instance at cp.vps.ezscale.tech:
all data sources return correct data with full pagination support.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

examples/resources/virtfusion_build/resource.tf

@@ -1,10 +0,0 @@
-resource "virtfusion_build" "node1" {
-  server_id = virtfusion_server.node1.id
-  name      = "node1-demo"
-  hostname  = "node1.example.com"
-  osid      = 1
-  vnc       = true
-  ipv6      = true
-  ssh_keys  = [virtfusion_ssh.dummy_key.id]
-  email     = true
-}

examples/resources/virtfusion_server/resource.tf

@@ -12,3 +12,7 @@ resource "virtfusion_server" "node1" {
   storage_profile        = 1
   network_profile        = 1
 }
+
+output "server_id" {
+  value = virtfusion_server.node1.id
+}

examples/resources/virtfusion_server_build/resource.tf

@@ -0,0 +1,10 @@
+resource "virtfusion_server_build" "node1_build" {
+  server_id = virtfusion_server.node1.id
+  name      = "my-server"
+  hostname  = "my-server.example.com"
+  osid      = 1
+  vnc       = true
+  ipv6      = false
+  ssh_keys  = [virtfusion_ssh_key.mykey.id]
+  email     = false
+}

examples/resources/virtfusion_ssh/resource.tf

@@ -1,9 +0,0 @@
-resource "virtfusion_ssh" "dummy_key" {
-  # This is what is displayed in the UI on the SSH keys page.
-  name = "dummy_key"
-
-  public_key = "ssh-rsa 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 dummy_key"
-
-  # This is the user ID that the key will be associated with.
-  user_id = 1
-}

examples/resources/virtfusion_ssh_key/resource.tf

@@ -0,0 +1,9 @@
+resource "virtfusion_ssh_key" "mykey" {
+  user_id    = 1
+  name       = "my-ssh-key"
+  public_key = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIExample user@example.com"
+}
+
+output "ssh_key_id" {
+  value = virtfusion_ssh_key.mykey.id
+}

examples/resources/virtfusion_user/resource.tf

@@ -0,0 +1,5 @@
+resource "virtfusion_user" "customer1" {
+  name            = "John Doe"
+  email           = "john@example.com"
+  ext_relation_id = "cust-12345"
+}